Incompatible remote shell (was: Can't create folder (because of fish shell on remote))

[TriplEight]

Spent an hour checking that everything else works. Please at least don't let this fail silently. cc #470

backintime-qt --backup:

DEBUG: [common/sshtools.py:664 SSH.checkRemoteFolder] Call command: ssh -o ServerAliveInterval=240 -o LogLevel=Error -o IdentityFile=/home/user/.ssh/backup -o Ciphers=aes192-ctr -p 22 [email protected] d=0;test -e "/run/media/user/share/backups" || d=1;test $d -eq 1 && mkdir "/run/media/user/share/backups"; err=$?;test $d -eq 1 && exit $err;test -d "/run/media/user/share/backups" || exit 11;test -w "/run/media/user/share/backups" || exit 12;test -x "/run/media/user/share/backups" || exit 13;exit 20
DEBUG: [common/sshtools.py:674 SSH.checkRemoteFolder] Command returncode: 127

remote test:

$ ssh -o ServerAliveInterval=240 -o LogLevel=Error -o IdentityFile=/home/user/.ssh/backup -o Ciphers=aes128-ctr -p 22 [email protected] d=0;test -e "/mounts/share/backups" || d=1;test $d -eq 1 && mkdir "/mounts/share/backups"; err=$?;test $d -eq 1 && exit $err;test -d "/mounts/share/backups" || exit 11;test -w "/mounts/share/backups" || exit 12;test -x "/mounts/share/backups" || exit 13;exit 20
fish: Unsupported use of '='. In fish, please use 'set d 0'.
d=0
^~^
mkdir: cannot create directory ‘/mounts/share/backups’: No such file or directory
exit